• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.575-581
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• 2022

Brown rats (Rattus norvegicusBerkenhout, 1769) were eradicated from Sasudo Island (33°55'13.04" N, 126°38'19.98" E), an uninhabited island designated as Natural Monument No. 333 and the largest breeding site for the streaked shearwater (Calonectris leucomelasTemminck, 1835) in South Korea. Twelve eradication studies were conducted from November 2015 to February 2021. The survey was conducted using a line census method that entailed slow wandering throughout the island and identifying starting and returning points. Capture traps were installed around traces of Rattus norvegicus,such as excrement and identified holes. As a result, 2 to 6 individuals were captured at each instance, except for the last time, when no individuals were captured. It is hypothesized that brown rats arrived at Sasudo Island via vessels arriving at the island for leisure and fishing. After the damage to streaked shearwater caused by brown rats was confirmed in 2006, entry to Sasudo Island was strictly prohibited through security measures, and marine clean-up programs that began in 2013 and continuous capturing since 2015 have been successful in eradicating brown rats. To maintain and manage the condition in Sasudo Island, preservation and management measures, such as strict visitor control, are necessary to prevent the inflow of new brown rats in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.465-474
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• 2023

As the effective use and strong protection of an organization's information resources are recognized as a condition for the growth of an organization, they are increasing technological and policy investments in IS(information security). However, information exposure can occur from external invasions such as hacking and incidents related to misuse and abuse by insiders. This study proposes a mechanism that considers the organizational environment and individual characteristics from the viewpoint of promoting employees' IS participation activities. In other words, the study presents the complex effects of organizational environmental factors (ethical leadership, IS collaborative communication) and personal factors (person-organization fit) on organization trust and IS voice behavior. We surveyed office workers who asked for IS-related business activities and tested hypotheses using 422 samples. As a result, ethical leadership influenced organization trust through collaborative communication, and organization trust strengthened IS voice behavior by having an interaction effect with person-organization fit. This study suggests direction for establishing an organizational environment for promoting IS-related activities by office workers, so it provides practical implications for organizations with goals related to internal information exposure control.

• Journal of the Korean Geotechnical Society
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• v.24 no.12
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• pp.65-73
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• 2008

In the current practice for slope stability problem in Japan, the shear strength, $\tau$, mobilized along the failure surface is usually estimated based on an empirical approximation in which the cohesion, c, is assumed to be equal to the soil thickness above the supposed slip surface, d(m). This approximation is advantageous in that the result of stability analysis is not influenced by the designers in charge. However, since the methodology has little theoretical background, the cohesion may often be grossly overestimated, and conversely the angle of shear resistance, $\phi$, is significantly underestimated, when the soil thickness above the supposed slip surface is quite large. In this paper, a case record of natural slope failure that took place in Hyogo Prefecture in 2007, is described in detail for the case in which the shear strength along the collapsed surface was carefully examined in a series of direct shear box (DSB) tests by considering the effects of in-situ shear stress along the slip surface. It is demonstrated that the factor of safety agrees with that of in-situ conditions when the shear strength from this kind of DSB test was employed for the back-analysis of the slope failure.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.2
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• pp.118-126
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• 2023

In accordance with the increased demand for ocean use, the Marine Spatial Planning system was introduced to rationally allocate ocean space, under which fishing activity protection zones have been designated to protect fishery activities and promote fishery resource protection. However, fishing vessels that mainly sail in fishing activity protection zones are exposed to risk, such that they account for about 70% of marine accidents that occur in Korea, Proper risk management is thus required. This study aims to analyze marine accidents in fishing activities protection zones and port and navigation zones to secure the safety of fishing vessels passing within fishing activity protection zones. To this end, the traffic volume in marine use zones was investigated, and marine accidents were investigated by ship type, accident type, tonnage, accident cause, and loss of life. Analysis determined that most of the marine accidents per unit area of each type occurred in port and navigation zones, but overall most marine accidents occurred in fishing activity protection zones. In particular, it was found that traffic safety management was necessary because many human accidents occurred.

• Journal of Technology Innovation
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• v.30 no.1
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• pp.1-20
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• 2022

Digital transformation refers to the economic and social effects of digitisation and digitalisation. Although digital transformation acts as a useful tool for economic/social development and enhancing the convenience of life, it can have negative effects (misuse of personal information, ethical problems, deepening social gaps, etc.). The government is actively establishing policies to promote digital transformation to secure competitiveness and technological hegemony, however, understanding of digital transformation-related risk issues and implementing policies to prevent them are relatively slow. Thus, this study systematically identifies risk issues of the future society that can be caused by digital transformation based on quantitative analysis of media articles big data through the Embedded Topic Modeling method. Specifically, first, detailed issues of negative effects of digital transformation in major countries were identified. Then detailed issues of negative effects of artificial intelligence in major countries and Korea were identified. Further, by synthesizing the results, future direction of the government's digital transformation policies for responding the negative effects was proposed. The policy implications are as follows. First, since the negative effects of digital transformation does not only affect technological fields but also affect the overall society, such as national security, social issues, and fairness issues. Therefore, the government should not only promote the positive functions of digital transformation, but also prepare policies to counter the negative functions of digital transformation. Second, the detailed issues of future social risks of digital transformation appear differently depending on contexts, so the government should establish a policy to respond to the negative effects of digital transformation in consideration of the national and social context. Third, the government should set a major direction for responding negative effects of digital transformation to minimize confusion among stakeholders, and prepare effective policy measures.

• Maritime Security
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• v.6 no.1
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• pp.109-135
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• 2023

The North Korean military's maneuver toward Honam was the fastest maneuver the North Korean army had demonstrated during the Korean War, and it was a threatening attack that forced the Korean and Allied forces to fully adjust the defenses of the Nakdong River. However, when this study analyzed the North Korean military's maneuver toward Honam in terms of indirect approach strategy, there were a number of factors that inevitably led to its failure. In terms of implementing the indirect approach strategy, the North Korean military cited a number of failure factors, including the dispersion of combat forces, the inflexibility of changing the line of operation, the maneuvering of ground forces, and the lack of psychological distaction. However, the North Koreans were preparing for a final "surprise attack," in which the 7th Division, which was following the North Korean 6th Division, took another diversion and attempted to attack in the direction of Tongyeong. With this, the North Koreans intended to break through the Nakdong River defenses and head for Pusan. However, the North Korean attack was ultimately thwarted by the Korean Navy and Marine Corps' Tongyeong Amphibious Operation. With a swift maneuver using the sea as a maneuvering space, the Navy and Marine Corps occupied key points first, creating an advantageous situation and fending off an attack by the North Korean 7th Division. The Navy and Marine Corps' Tongyeong Amphibious Operation finally thwarted the North Korean military's maneuver toward Honam, thus maintaining the Nakdong River defenses.

• Journal of Radiation Protection and Research
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• v.47 no.4
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• pp.237-245
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• 2022

Background: The current study reports measurements of activity concentrations of radon (²²⁰Rn) and thoron (²²⁰Rn) in dwellings, followed by inhalation dose assessment of the public, and then by the development of regulation and the national radon action plan (NRAP) in Cameroon. Materials and Methods: Radon, thoron, and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings. From 2019 to 2020, radon track detectors (commercially RADTRAK) were deployed in 1,400 dwellings. It was found that activity concentrations of radon range in 1,850 houses from 10 to 2,620 Bq/㎥ with a geometric mean of 76 Bq/㎥. Results and Discussion: Activity concentrations of thoron range from 20 to 700 Bq/㎥ with a geometric mean of 107 Bq/㎥. Thoron equilibrium factor ranges from 0.01 to 0.6, with an arithmetic mean of 0.09 that is higher than the default value of 0.02 given by UNSCEAR. On average, 49%, 9%, and 2% of all surveyed houses have radon concentrations above 100, 200, and 300 Bq/㎥, respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40%. Thus, thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies. Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020. Reference levels of 300 Bq/㎥ and 1,000 Bq/㎥ were recommended for dwellings and workplaces. Conclusion: Priority actions for the coming years include the following: radon risk mapping, promotion of a protection policy against radon in buildings, integration of the radon prevention and mitigation into the training of construction specialists, mitigation of dwellings and workplaces with high radon levels, increased public awareness of the health risks associated with radon, and development of programs on the scientific and technical aspects.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.327-332
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• 2023

On December 26, 2022, North Korea's drone provocation resumed for the first time in eight years. The threat covered not only the Seoul metropolitan area but also the no-fly zone for the presidential office's security, and the South Korean military's response to it is not appropriate, which is a major controversy. In the midst of this, problems caused by the prohibition of small drones' flight and illegal intrusion into restricted areas are increasing in Korea, and the threat is becoming a reality, such as being used for terrorist attacks abroad. In this paper, the concept of "Counter-Drone" and related technologies were considered for these drone threats, and implications were derived through domestic and overseas small drone threats, and the direction of development of the Counter-Drone system was presented. North Korea's drone threat is expected to be more diversified, massified, and advanced, resulting in bolder attacks and provocations. Therefore, the South Korean military should push for early powering of the integrated control system and the conter drone system, joint and military cooperation in response to the threat of small drones, and the ability to carry out joint operations between South Korea and the U.S.

• International Area Studies Review
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• v.15 no.1
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• pp.87-106
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• 2011

Using an event study, this paper investigates stock price reactions on Korean listed firms' convertible bond (CB) issue announcements over the sample period of January 2000 to November 2007. This study finds that on the Korean Security market, the CB issue announcements are associated with an increase in shareholder wealth on the announcement date. An information leakage by insider traders is also observable at preannouncement dates. Unlike the prior studies that indicate a prevailing negative effect on the announcements, this paper shows that domestic CB issue announcements as well as offshore ones yield a positive impact on the stock prices. This presents that in terms of stock price reactions to the CB issue announcements, the two CB issue markets show the positively same effects on shareholder wealth for the post-2000 period. For its drivers, this paper suggests that on the Korean market, firm size have negative relationship with the increase in the wealth incurred by the announcements. By contrast, an issue to maturity, a growth opportunity, and a relative issue size make a positive impact on it.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.67-76
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• 2023

Although deep learning models are making innovative achievements in the field of computer vision, the problem of vulnerability to adversarial examples continues to be raised. Adversarial examples are attack methods that inject fine noise into images to induce misclassification, which can pose a serious threat to the application of deep learning models in the real world. In this paper, we propose a model that detects adversarial examples using differences in predictive values between edge-learned classification models and underlying classification models. The simple process of extracting the edges of the objects and reflecting them in learning can increase the robustness of the classification model, and economical and efficient detection is possible by detecting adversarial examples through differences in predictions between models. In our experiments, the general model showed accuracy of {49.9%, 29.84%, 18.46%, 4.95%, 3.36%} for adversarial examples (eps={0.02, 0.05, 0.1, 0.2, 0.3}), whereas the Canny edge model showed accuracy of {82.58%, 65.96%, 46.71%, 24.94%, 13.41%} and other edge models showed a similar level of accuracy also, indicating that the edge model was more robust against adversarial examples. In addition, adversarial example detection using differences in predictions between models revealed detection rates of {85.47%, 84.64%, 91.44%, 95.47%, and 87.61%} for each epsilon-specific adversarial example. It is expected that this study will contribute to improving the reliability of deep learning models in related research and application industries such as medical, autonomous driving, security, and national defense.